Endoscopes have attained great acceptance within the medical community, since they provide a means to perform procedures with minimal patient trauma, while enabling the physician to view the internal anatomy of the patient. Over the years, numerous endoscopes have been developed and categorized according to specific applications, such as cystoscopy, colonoscopy, laparoscopy, upper GI endoscopy and others. Endoscopes may be inserted into the body's natural orifices or through an incision in the skin.
An endoscope is usually an elongated tubular shaft, rigid or flexible, having one or more video cameras or fiber optic lens assemblies at its distal end. The shaft is connected to a handle, which sometimes includes an ocular for direct viewing. Viewing is also usually possible via an external screen. Various surgical tools may be inserted through a working channel in the endoscope to perform different surgical procedures.
Endoscopes may have a front camera and a side camera to view the internal organ, such as the colon, illuminators for each camera, one or more fluid injectors to clean the camera lens(es) and sometimes also the illuminator(s) and a working channel to insert surgical tools, for example, to remove polyps found in the colon. Often, endoscopes also have fluid injectors (“jet”) to clean a body cavity, such as the colon, into which they are inserted. The illuminators commonly used are fiber optics which transmit light, generated remotely, to the endoscope tip section. The use of light-emitting diodes (LEDs) for illumination is also known.
The elongated tubular shaft, also known as the insertion portion of the endoscope has a bending section, proximal to a distal end of the shaft that can bend upon application of an external control to navigate a curved path inside a body cavity, or to access difficult areas within the cavity. However, sometimes it is desirable to vary the degree of bending, based on the application or based on the region inside the body cavity where a distal end of the shaft is navigating. A stiffer insertion portion may reduce the chances of looping of the tubular shaft inside the body cavity, whereas a softer insertion portion may make it easier to reach the cecum. Lack of the ability to vary the stiffness of the insertion portion, such as around the bending portion, could result in patient discomfort and/or increased time for endoscopic examinations. Additionally, some physicians may prefer using a stiffer insertion portion, while some others may prefer a flexible insertion portion. Moreover, repeated reprocessing of parts of endoscope, including its cleaning, may influence the flexible characteristics of the insertion portion. As a result, the insertion portion may become more flexible than required with each time it is cleaned.
U.S. Pat. No. 7,789,827, assigned to Storz, discloses “a flexible endoscope comprising: a flexible shaft portion having a distal and a proximal end and including an outer layer comprising an electrically insulated water-tight material, an inner layer enclosed by said outer layer, a plurality of elongated segments disposed in said outer layer and comprising a polymer material that changes characteristics upon the application of an electrical current, a handle portion coupled to said flexible shaft portion, an electrical source for providing the electrical current to said at least one elongated segment, and electrical conductors electrically connected between said plurality of elongated segments and said electrical source, said electrical conductors extending from said flexible shaft portion through said handle portion to said electrical source, wherein said plurality of elongated segments are positioned in said outer layer in an end-to-end fashion along a longitudinal length of said flexible shaft portion and each elongated segment has at least one end affixed to said inner layer such that upon an application of electrical current to said plurality of elongated segments, said plurality of elongated segments change physical dimension, and wherein said inner layer moves relative to said outer layer based on the dimensional change of at least one of said plurality of elongated segments.” However, the '827 patent does not provide a complete mechanical control of the flexibility of the insertion portion.
Thus, what is needed is an insertion portion with an ability to vary its stiffness or flexibility, with minor modifications to the existing structure, shape, size, and manufacturing complexity. Additionally, what is needed is a flexible shaft with an insertion portion that may utilize material available with an endoscope system.